The new linkage is intended to mount in the 1/2"
upper hole on Holley carburetor throttle arms. A bushing
must be used to reduce this hole. The chrome stepped
bushings in this photo are available from Moroso and
others for about $5. However in a pinch these rubber
insulated washers work nicely, and are available for
pennies at the hardware store (usually on self tapping
metal screws as seen here.)